Question

solid lead(ii) sulfide reacts with aqueous hydrobromic acid (hbr) to form solid lead(ii) bromide and dihydrogen sulfide gas. express your answer as a chemical equation. identify all of the phases in your answer. a chemical reaction does not occur for this question. submit request answer part b gaseous carbon monoxide reacts with hydrogen gas to form gaseous methane (ch₄) and oxygen gas. express your answer as a chemical equation. identify all of the phases in your answer.

Explanation:

Step1: Write reactants and products for first reaction

Solid lead(II) sulfide ($PbS(s)$), aqueous hydrobromic acid ($HBr(aq)$) are reactants. Solid lead(II) bromide ($PbBr_2(s)$) and dihydrogen sulfide gas ($H_2S(g)$) are products.

Step2: Balance the first reaction

$PbS(s)+2HBr(aq)
ightarrow PbBr_2(s)+H_2S(g)$

Step3: Write reactants and products for second reaction

Gaseous carbon - monoxide ($CO(g)$) and hydrogen gas ($H_2(g)$) are reactants. Gaseous methane ($CH_4(g)$) and oxygen gas ($O_2(g)$) are products.

Step4: Balance the second reaction

$2CO(g) + 4H_2(g)
ightarrow 2CH_4(g)+O_2(g)$

Answer:

$PbS(s)+2HBr(aq)
ightarrow PbBr_2(s)+H_2S(g)$
$2CO(g) + 4H_2(g)
ightarrow 2CH_4(g)+O_2(g)$